TIP #1 - INCREASING FM COVERAGE
For example one of the most important considerations of your activity,
for those that have FM broadcast stations, is to anticipate your
coverage. Accordingly, I am attaching a chart which indicates the
anticipated coverage for specific ERP's and at various elevations above
average terrain. This information reflects the distance from your
transmitter site to a 500 microvolts per meter field strength. We have
found that this field strength is quite adequate to penetrate the walls
of average buildings. If you have any questions about this chart, please
do not hesitate to contact me. We will keep this chart in this file for
future reference and as equivalent technical data of this complexity
appears, I will include it in this presentation.
PREDICTED FM COVERAGE DATA
|
E.R.P
|
.01 kW |
.1 kW |
.5 kW
|
1 kW |
|
3 kW |
5 kW
|
10 kW |
25 kW |
50 kW |
100 kW |
| H.A.A.T (in ft.) |
coverage (in miles) |
coverage (in miles) |
coverage (in miles) |
coverage (in miles) |
coverage (in miles) |
coverage (in miles) |
coverage (in miles) |
coverage (in miles) |
coverage (in miles) |
coverage (in miles) |
coverage (in miles) |
| 100 |
2.9 |
5.1 |
7.6 |
9.0 |
9.9 |
11.7 |
13.3 |
15.6 |
19.3 |
22.6 |
26.3 |
| 150 |
3.5 |
6.3 |
9.4 |
11.2 |
12.3 |
14.5 |
16.3 |
19.0 |
23.2 |
26.8 |
30.7 |
| 200 |
4.0 |
7.3 |
10.9 |
12.9 |
14.1 |
16.6 |
18.6 |
21.6 |
26.0 |
29.8 |
33.9 |
| 250 |
4.5 |
8.1 |
12.1 |
14.3 |
15.7 |
18.3 |
20.4 |
23.6 |
28.3 |
32.2 |
36.3 |
| 300 |
4.9 |
8.9 |
13.2 |
15.5 |
17.0 |
19.8 |
22.0 |
25.3 |
30.2 |
34.2 |
38.4 |
| 350 |
5.3 |
9.6 |
14.2 |
16.6 |
18.2 |
21.1 |
23.4 |
26.9 |
31.9 |
35.9 |
40.3 |
| 400 |
5.7 |
10.3 |
15.1 |
17.7 |
19.3 |
22.3 |
24.7 |
28.3 |
33.4 |
37.5 |
41.9 |
| 450 |
6.1 |
10.9 |
15.9 |
18.6 |
20.3 |
23.4 |
25.9 |
29.5 |
34.7 |
39.0 |
43.4 |
| 500 |
6.4 |
11.5 |
16.7 |
19.5 |
21.2 |
24.5 |
27.0 |
30.7 |
36.0 |
40.3 |
44.8 |
| 550 |
6.7 |
12.0 |
17.5 |
20.3 |
22.1 |
25.4 |
28.0 |
31.8 |
37.2 |
41.5 |
46.1 |
| 600 |
7.0 |
12.6 |
18.2 |
21.1 |
23.0 |
26.3 |
29.0 |
32.9 |
38.3 |
42.7 |
47.3 |
| 650 |
7.3 |
13.1 |
18.9 |
21.9 |
23.8 |
27.2 |
29.9 |
33.8 |
39.4 |
43.8 |
48.4 |
| 700 |
7.6 |
13.6 |
19.5 |
22.6 |
24.5 |
28.1 |
30.8 |
34.8 |
40.4 |
44.8 |
49.5 |
| 750 |
7.8 |
14.0 |
20.2 |
23.3 |
25.3 |
28.9 |
31.7 |
35.7 |
41.3 |
45.8 |
50.5 |
| 800 |
8.1 |
14.5 |
20.8 |
24.0 |
26.0 |
29.6 |
32.5 |
36.5 |
42.2 |
46.8 |
51.5 |
| 850 |
8.4 |
14.9 |
21.4 |
24.6 |
26.7 |
30.4 |
33.2 |
37.3 |
43.1 |
47.7 |
52.4 |
| 900 |
8.6 |
15.3 |
21.9 |
25.3 |
27.3 |
31.1 |
34.0 |
38.1 |
43.9 |
48.6 |
53.3 |
| 950 |
8.8 |
15.8 |
22.5 |
25.9 |
28.0 |
31.7 |
34.7 |
38.9 |
44.8 |
49.4 |
54.2 |
| 1000 |
9.1 |
16.2 |
23.0 |
26.4 |
28.6 |
32.4 |
35.4 |
39.6 |
45.5 |
50.2 |
55.0 |
| 1050 |
9.3 |
16.6 |
23.5 |
27.0 |
29.2 |
33.1 |
36.1 |
40.3 |
46.3 |
51.0 |
55.8 |
| 1100 |
9.5 |
16.9 |
24.0 |
27.6 |
29.7 |
33.7 |
36.7 |
41.0 |
47.0 |
51.7 |
56.6 |
| 1150 |
9.7 |
17.3 |
24.5 |
28.1 |
30.3 |
34.3 |
37.3 |
41.7 |
47.7 |
52.4 |
57.3 |
| 1200 |
9.9 |
17.7 |
25.0 |
28.6 |
30.9 |
34.9 |
38.0 |
42.3 |
48.4 |
53.1 |
58.1 |
| 1250 |
10.1 |
18.0 |
25.5 |
29.1 |
31.4 |
35.4 |
38.6 |
43.0 |
49.0 |
53.8 |
58.7 |
| 1300 |
10.3 |
18.4 |
25.9 |
29.6 |
31.9 |
36.0 |
39.1 |
43.6 |
49.7 |
54.5 |
59.4 |
| 1350 |
10.5 |
18.7 |
26.4 |
30.1 |
32.4 |
36.5 |
39.7 |
44.1 |
50.3 |
55.1 |
60.1 |
| 1400 |
10.7 |
19.0 |
26.8 |
30.6 |
32.9 |
37.0 |
40.2 |
44.7 |
50.9 |
55.7 |
60.7 |
| 1450 |
10.9 |
19.4 |
27.2 |
31.0 |
33.4 |
37.6 |
40.8 |
45.3 |
51.5 |
56.3 |
61.3 |
| 1500 |
11.0 |
19.7 |
27.6 |
31.5 |
33.8 |
38.1 |
41.3 |
45.8 |
52.0 |
56.9 |
61.9 |
NOTE: *H.A.A.T is the Height Above Average Terrain at center of
radiation. **E.R.P. is Effective
Radiated Power.
|
When reviewing this predicted FM coverage chart, you will notice
that a difference in elevation has a much more substantial effect over the
coverage than the actual ERP. In other words, raising the radiated power 2:1
might increase the range by approximately 3 to 5 miles, but doubling the
elevation will give you possibly 33% increase in range.
Best of luck in your technical activities